On Linux, writing accents using a compose key isn't much slower than typing the letters directly either.
1. french people I know who use qwerty tend to not write any accentuated characters anymore. I'm ready to accept compose keys are usable, but it clearly seems to encourage incorrect spelling when you use a language with a lot of accentuated characters in a sentence
2. vim. I really don't see myself fighting to remap my habits and workflows, given what I perceive as very few benefits switching layout would provide
Regarding your concern with accents: Under Linux I am using English (International with AltGr dead keys) which allows me to compose accents by pressing AltGr then the key(s) that represent the accent and then the base character. So for à I press AltGr+Backtick and then 'a'. The advantage is that it gives me all of the accents that I need in Europe - there is no problem in writing German äÄöÖüÜß, and even for French you can easily have a œ in cœur - I would not even know how to get this one on an azerty keyboard.
For Windows there is as well a possibility to install this layout.
The other advantage is, that if you work a lot with different countries - I am remotely often on customer's computers via different remote sessions - then no matter what country, you always have qwerty - on Windows it's normally just one Alt+Shift away.
Definitely good investment and I will not go back (by the way I had to learn 3 layouts in my life - German, then French and now I am so happy with qwerty.
If I remember correctly it's slightly easier to type é and è on an azerty keyboard, but not that much.
2. vim is qwerty centric, the best example for me was using CTRL-[ instead of ESC which actually makes sense on a qwerty but not on an azerty. It doesn't take that much time to learn new habits.
Overall, I would advise against changing your layout unless there's another good reason. I decided to switch because I was using many computers with a qwerty layout, and only my personal computer was still with an azerty layout. It sounded more productive to just have one layout instead of having to think about it.
A side note, btw, regarding CTRL-[ : it seems not to be well known, and it doesn't work on things that use "alt" to access file menu (like gvim), but using alt + <normal mode key> in insert mode instantly drops to normal mode and execute that key. For example, I usually leave insert mode by doing A-j or A-h, I never hit the ESC key.
My favorite trick is `A-e a` when inside parenthesis to jump just after it and still be in insert mode, like when writing parameters to a function and jumping out of parameters list to add the `{` character.
I don't think it's at all clear, because most people don't have a compose key - only linux does that.
> vim. I really don't see myself fighting to remap my habits and workflows, given what I perceive as very few benefits switching layout would provide
Being able to use a default vim is very useful, and the default vim is qwerty-oriented. (It took me a long time to learn to use hjkl on Dvorak).
Especially given that æøå are generally using the triangle right of p and l, and so messing with my brackets and braces.
I remember those well enough that I have no reason to have them on the keyboard, which doesn't make it particularly inconvenient not to have them on the keys, and I can always switch to US layout with a quick keyboard combo if I need a character I don't remember the position of on Norwegian layout.
Of course, it helps that I live in the UK where the layout differences between US/UK keyboards are minor, so I'm not particularly inconvenienced when I have to use someone else's keyboard - if I lived in Norway I'd probably have stuck to a Norwegian layout.
This allows me to use a single functional keyboard layout to write English, Norwegian _and_ code in.
You could easily add å if you want.
I have also tied CapsLock to the Nordic layout (Swedish/Finnish), so when CapsLock is on, you can blindly type and get those öäå characters on a regular qwerty layout. I never seem to use that, but at least I'm rid of CapsLock. ;)
I write both code and text in different languages, and in international environments just getting used to a standard qwerty layout has turned out to be the most efficient option.
Consolekeys (I think that's still it) for console, xmodmap for Xorg.
Generally, Xorg will prompt you for the desired layout anyhow.
Mind, the labeling on the physical keyboard itself may not match. I generally don't even look at the keyboard when typing, so that's not an issue.